Methods for processing thermoplastic yarns



Sept. 3, 1963 i ,7 N. E. KLEIN ETAL METHODS FOR PROCESSING THERMOPLASTIC YARNS Original Filed June 9, 1958 5 Sheets-Sheet 1 INVENIOR. NORMAN E. KLEIN BY CYRIL G. EVANS Wzfi fw ATTORNEY Sept. 3, 1963 N. E. KLEIN ETAL 3,102,321

METHODS FOR PROCESSING THERMOPLASTIC YARNS Original FiledJune 9, 1958 5 Sheets-Sheet 2 4- 3 9k 304 320 322 305 3|e( J /I o o) I [IV/ll A'III 48 3/ INVENTOR. NORMAN E. KLEIN CYRIL G. EVANS BY aw 5M ATTORNEY Sept. 3, 1963 N. E. KLEIN ETAL 3, 3

METHODS FOR PROCESSING THERMOPLASTIC YARNS Original Filed June 9, 1958 5 Sheets-Sheet 3 INVENTOR. NORMAN E. KLELN OYRIL e. EVANS ATTORNEY Sept. 3, 1963 N. E. KLEIN ETAL 3,102,321

METHODS FOR PROCESSING THERMOPLASTIC YARNS Original Filed June 9, 1958 5 Sheets-Sheet 4 79 as as 84 "'3 I ,zes 2254 226 I 24 1258 22a |||I 3% as W230 A 224 22% |9o V// 1 423 k I96 '288 |94 202 I93 52 204 Illlllil 1 nu- INVENTOR. NORMAN E. KLEIN F/6. 6 CYRIL G.EVANS ATTORNEY Sept. 3, 1963 N. E. KLEIN ETAL 3,102,321 METHODS FOR PROCESSING THERMOPLASTIC YARNS Original Filed June 9, 1958 5 Sheets-Sheet 5 INVENIOR. NORMAN E. KLEIN CYRIL G. EVANS ATTORNEY it and this application.Fehgltlgilgfil pose, but 'inuth-is specification no distinction between yarnsproducedwiththe ditferenttypes o twisti ing apparatus, and all such yarns are'referfedto' l 1 processed in this mannertis only partially apparent r continuous fiil-ament, thermoplastic yarns conipris f- R t steps of mechanically crimping the yarn andheat-setting the resulting crimptherein. The mechanical Crimping necessary'inasuch processescan be accomplished by any one of several different procedures such as passingthe Patented 1 963 r 7 3;1o2,3'21L METHODS FOR PROCESSING T E QPLASTICYARNS" Norman El Klein and Cyril G. Evansyspartanburg, S .C., assiguors to Deering Millikan Research Corporation,

Spartanburg,S'.C.,a corporation of Delaware y m through a pair ofinatchjngcorru-gated rolls, forcing,

theyarnyinto'a'crimping' chamber or by knitting the yarn' Y into a closely knit fabric from which it, is subsequently unraveled, and'yarns produced by all such methodsare referred to in this specification as mechanically crimpedt Original. applicationJuneD, .1958,Ser. No.740,6s7;;bw

Patent No. 2,977,746,vdatedj,Apr. 4,!1961. Divided This invention relates to methodsIor processing yarns and more particularly the invention relates to methods for thermally treating I thermoplastic yarns feinployi-rig novel apparatus whichican beemployed for post-treating oneor more elasticized yarnsjedge crimping one or 'sev- I eralithermoplasticyarns; for simultaneously edge crimp ing and post-treating one orseveral'ela s ticized yarnsin a combined operation; I; and for performingivari ousotherl operations .andlcombinationsot openationsiupon thermoplasticyarns. This is a division of our application Serial Patent No.2,977,74'6;.p g V, r t t i There are commercially available any nuiriberbf so called elasticized or stretch yar'ris which areiemployed in' rth e knitting of stockings, sweaters; blouse's, sheetsand1 other articles oftliis typeand for the knitting of fabrics employed in the manufacture ofv such articles. LIn most instances the primary reason for employing an elasticized" characteristics as a result of being fabricatedfrlom elas-r w ticizedyarns have been widelyaccepted and are presently sold in large volumes, 4 i i An elastic nature can be impartedlto a thermoplastic false-twisting apparatus especially designed for the PUT:

A second procedure for iinparting anelastic nature to.

to thereby stress the yarn such that -the Ifilanients thereof jSrlNo. 88,384 a a yarn supply means, afirst-yar-n advancing-means, a

4 Number 740,637, file-d June9, 1958, now United States treating apparatus.

yards.

ltlhasrecently been cfiound that thecharacteristics of especially advantageous for certain applications, and increasing quantities j ofelasticized yarns are being thus treated; The apparatus employed for posPtre'ating'elasticized yarns in this mannerfc'omprises, in most instances,

plate-type haterga second advancing means which advances the yarn at: a slower rate; than the first yarn advancing means, and'iayarn collecting means. This ap' par atus is completely separate from the yarn elasticizing. I p apparatus, and the fact that separate apparatus is' re'quired" for the, elasticizing and post-treating operation's'unecessi tatesjarel'atively high'expenditure for equipment andfioor separateyarn theaters used in the 'elasticizing andg post It isari object: of invention to provide irnproved: methods'for post-treating elasticized yarns. 1

' It is anotherobjectof thisiriv'ention to provide 1rnethaods, utilizing asingle lieater, which can beemployed for; sirnultancouslyedge e-lasticizi'ng and post-treating a ther-v moplasticyam.

It is another object of the invention to provide methodsfor velasticizing' and post-treating a plurality of yarns,

, plied yarnof relatively high total denier.

renew assumeaghighly convoluted configurationm This method ofelasticizing continuous fiiarfdent,v thermoplastic: yarns is highly desirable for the reason t-hat"yarns-elas-:

ticized by this method nonmal'ly have little or no tendency-to' twistand can readily-heemployedhsingleplyQ a It also difiers from mosttother methods of elasticiiing thermoplastic yar-ns that the elastic -nature a ya r n ing pfassage ofithe yarn about the blade edge and heat a l treatment is necessaryto develop its full elastic mi,t'uregi Yarns elasticized by this procedure are reie'rred toj specification as fe dge elasticizedyarns. L Still other methods for imparting an elastic n v largenporti'on vofythe heater andfeed the same to the.

and forthereafter twisting thefyarns together tovfornr a;

..It isstillanother-object of the invention to provide improved methods for, perfoi'n'nirigs one or more processing operations, at least one bf "which utilizes elevated temperatures, upon" one or a plurality of ends of thermoplastic IfAccordingfto-thisinvention there employed apparatus comprising" arotary heater," 3. yarn advancing means tof-advance-onenor a plurality of ends of thermoplastic yarn 'tol-said rfotary heater at a'firstselected linear" rate, a second yarn advancing-:means to withdraw said one or more ends of yarn from the yarn heater at a second linear rate, andmeanslo rotate said yarn heater such that ithas a selected surtfa'ce speed relative to the v A t an end of yarn comprises passing itpwhileat an elevated temperature-about the sharpened edge of a blade member rate at which said one or more ends of yarn are advanced; by the yarn advancing means. Preferably the vyarn:

heater comprises'a stepped roll having two different heat: ing surfaces of different wcliameters and the apparatus prefenably comprises s't-ill 'anothe'r yarn advancingmea-ns to advance one or morexends of thermoplastic yafnlt'othe larger diameter portion of the stepped roll heater;;and-

* a blade meanswith anledge operatively positioned 'closely adjacent thelarger diameter portion of saidrheater suchthat said oneor more endseofyarncan be withdrawn from the larger diameter portion of said yarnheater" and about the edge of said blade member in an acutely pains, With this'construction the smaller diameter pora tion of the yarn heater canQ-be'employed fora post-treat-w ment operation and asingle yar'n advancing means can be '=employed to'withdravv the yarn or yarns from the smaller diameter 7 portion of y the theater. '.The apparatus- 1 isalso-prefierably providedwith driving means of a' novel type to be subsequently described which enables one to" readily vary the relative rate of advance of the yarn by I the several yarn=advancingmeans= f; post treating operation, such above described;

performed in instances when it is desired to impart to a yarn an exceedingly bulky nature, and apparently results in this characteristic being imparted to a yarn by providing conditions which are favorable to the crimps in adjacent filaments of the yarn being formed out of phase, the word crimps being here employed to include undulations, coils, and kinks. In other words, at the point where the yarn comes into contact with the yarn heater in a process of this type, there is no lateral restraint on the yarn, and the restraint to the forward motion of the yarn offered by theyarn heater promotes lateral expansion of the yarn at a point in the yarn path immediately preceding the yarn heater. Lateral expansion of the yarn results in the filaments thereof being spatially separated so that the crimps in each filament can form independently and such that the crimps in adjacent filaments are largely out of phase or at least do not precisely coincide. It will readily be seen that a yarn can have a high measure of elasticity with very little bulk if the crimps in adjacent fibers are largely in phase but that if the crimps are out of phase, this results in adjacent yarn fibers being normally held apart from each other except for periodic spaced points of contact.

In addition to providing conditions such that the crimps in adjacent yarn fibers tend to initially form out of phase, the overfeed thermal treatment also serves to at least partially heat-set the crimps in this condition to thereby reduce the tendency for the crimps, after they have been removed by tensionin-g the yarn, to reform such that they are largely in phase. Further, the overfeed thermal treatment acts to at least partially stabilize the yarn so that its degree of elasticity i not subsequently subject to such large changes as a result of the release of latent stresses and, in the case of edge'elastic-ized yarns, also serves to develop a portion of the crimp which was originally latent in nature.

The use of a rotary heater for performing an overfeed thermal treatment on an elasticized yarn has been found to be surprisingly advantageous, and this is particularly so, in the case of edge elasticized yarns. Heretofore, it has been a general practice to employ a stationary plate heater for post-treating elasticized yarns and such posttreated yarn have been generally satisfactory, but it has now been found that the tension necessary to slide an elasticized yarn over the surface of a yarn heater, at least in some instances, adversely affects the properties of the yarn and that one can obtain a yarn having a higher degree of stabilized crimp and appreciably greater bulk, other factors being equal, with a rotary heater than with a plate heater. Further, the rate of heat transfer to the yarn with a rotary heater is excellent so that heatsetting of the yarn can be accomplished in a very short period of time and relatively high yarn velocities can be maintained without sacrificing quality in the finished product. 1

A preferred specific embodiment of apparatus em ployed in the process according to this invention will now be described with reference to the accompanying drawings in which:

FIGURE 1 is a schematic view in perspective showing principal parts in location.

FIGURE 2 is a front elevational view of the crimping and/or heat-treating component of the apparatus of I FIGURE 1.

FIGURE 3 is a side elevation view of the crimping and/ FIGURE 7 is an enlarged cross-sectional view of the heater roll assembly taken substantially along line 77 in FIGURE 4.

FIGURE 8 is a cross-sectional view of the unheated guide'roll assembly taken substantially along line 8--8 of FIGURE 4.

FIGURE 9 is a bottom view of one end of the blade holder am.

With reference to FIGURE 1 of the drawings in greater detail, there is illustrated a frame member 10 which can be and preferably is a portion of a conventional downtwister frame, and supported by member 10 is a plurality of yarn supply means two of which are illustrated and generally indicated by the reference numerals 12 and 14. Yarn supply means 12 and 14 comprise respectively spindles 16 and 17 for centrally supporting pirns or the like of yarn 18 and 19 so that ends of yarn 20 and 22 can be withdrawn from the pirns in an over-end manner through guide means 24 and 26, positioned on the extended central taxes of spindles 16 and 17. As will subsequently be more apparent, the apparatus of this invention can be employed to simultaneously'process four or more ends of yarn by the provision of a corresponding number of yarn supply means, but for a full understanding of the invention only two supply means need be illustrated.

From guide means 24 and '26 the yarn ends 26 and 22 are passed to tension regulators 28 and 30 which can be and preferably are of the design disclosed in U. S. Patent 2,790,611. The ends 20 and '22 are then passed to a combination edge crimping and heat-treating assembly which is generally indicated by'reference numeral 32, and which will subsequently be described in greater detail. After beingelasticized and/or post-treated, the yarn ends 20 and 22 are guided about an oil roll 34 which dips into a supply of oil within a trough 36 and is rotated by an electrical motor 38 at a rate calculated to supply an amount of oil to the yarn ends 20 and 22 to place them in a proper condition for weaving, knitting, or the like. The yarn. ends 20 and 22 are then passed through a guide 40 to a twisting and take-up means generally indicated by the reference numeral 42 and here illustrated as comprising a conventional ring and traveler array. The means 42 twists the ends of yarn 2t) and 22 to form a plied yarn which is then collected on a suitable core or the like indicated by the reference numeral 44.

The apparatus also includes driving means (not illustrated) for the take-up means 42 and means to selectively engage and disengage the driving means so that operation of the take-up'means'can be temporarily discontinued in caseof a yarn break or to replace the cone 44 when it has collected a full supply of yarn. These two components of the apparatus can suitably be of conventional design and construction, however, and for this reason will not be described in detail.

With particular reference to FIGURES 2 to 9 of the drawings, there is illustrated two support members 46 and 48 to which there is secured by means of bolts 49 and 50 a support housing 52 and secured to the upper edge of housing 52 by means of screws 54- and 56 is an arm 58 having on its upper extremity an integrally formed bracket member 60 for supporting yarn tensioners 28 and 30. Also supported by arm member 58 is a first guide means 62 preferably formed of a ceramic material and having a plurality of guide channels 64 for maintaining the ends of yarn 20 and 22 in spaced relationship. Positioned immediately below guide member 62 and also supported by arm 58 is a comb type guide means 66 having a plurality of pin members 68. The guide member 66 is adjustable pivotally in a generally vertical plane by virtue of being secured by a single screw 69 which can be loosened for adjustment of the guide means 66.

Journaled through a bushing member 70 and freely r0- tatable as a result of being mounted in antifriction bearings 71 and 72, is a shaft 73 which carries one roll 74 of a first yarn advancing 77 in one, side wall of support housing 52 and is secured d in position by a nut 78 which threadably engages the external end of the bushing. Thennut78 also serves to, se-

cure one end of an elongated support plate 79 having an' opening through which bushing extends and this construction has the, advantage that it permits plate 79 to be pivoted, for position adjustment purposes, about the central axis of shaft 73 by loosening nut 78. Theplate 79 gcarries a stub shaft 80 extending at,a small angle to the axis ofshaft 73 and about which is journaled a second roll382 of yarn advancing means 7 6.

Yarn. advancing means 76 is a double yarn advancing means designed to positively advance a plurality ofs trands means generally indicated by the. reference numeral 76. Bushing 7ll'cxtends through a slot terial" such as stainlesssteelf Since, however, such materials generally do not have a high thermal conductivity,

members'130 and 132 shouldbe relatively thin in radial thickness and should be in contact with heat distributing member 128 over as large an area as possible ;The

member 128 is preferably formedfrom a material such as copper having a relatively high coefiicient of thermal of yarn on two different occasions at two different linear rates, and for this reason each .ofrolls 74 and '82 are 'providedwith corresponding portions ofdifferent diame-.

ters. Roll 74 has a first portion, 84 of larger diameter which is separated by a flange86 from: a second portion 88 of smaller diameter, and roll '82 ha'sfcorresponding' portions 90 and 92, separated by aflange 94. Rolls 74 and 82 are provided with peripheral grooves 96 and 98 respectively, and a drive belt 100*i'ests within grooves r96, and 98.,andextends about rolls 74-and 82 toinsure that the two rolls are rotated such that corresponding portions, thereof have the same surface speeds. Ihe yarn ends 20 and 22 pass through tension regulators 28 and 30, about guide means 62 and 66,9.1'1Cl wrap one or more turns about rolls 74 and 82 so that they are positively advanced along the yarn path ata selected linear rate dependent upon the rate ofrotation of the rolls Hand 82. a As a result of the axis of rotation of roll 74being at an angle to the axis of rotataion of roll 82,,adjacent wraps of yarn about the two rolls remain in spaced relationship l and there is little or noabrasionof the yarn.

, i From the yarn advancing means 76, the yarn ends 20 and 22 are passedin spacedrelationship through a comb type guide means 102 secured to alaterally extending appendage 104 of arm .by any suitable means such as screw 106, and are thereafter passed to" a .yarn heater generally indicated by the reference numeral 108w The heater 108 comprises a stepped roll110 carried by a shaft 1 112 (see FIGURE 7) journaled through antifriction bear and cup 122 are provided for introducing-a lubricant to the surface of shaft. 112 intermediate bearings 114 and i 116. Carried by one end of shaft llz'is -a hubrmember ,124 from which extend a pluralityof legs,one,ofj which is visible at 126, for supporting an annular heat distribun.

ing an annular heat distributing member 128 L shaped in cross section. T he number of legs carried by hub 124 should be the minimum necessary for adequate support f temperature of bearingmer'nbers 114-and 116 are held to a minimum,

Heat distributing member 1zssrjves as a support for 'a first annular yarn contact member 130 and a second 1 annular contact member 132 of smaller diameter ,pro-

vided, in each instance, with yarn guide, grooves, 134 and 136 respectively, which serve'to maintain a plurality of ends of yarn, whilein contactwith the peripheral surfaces of members 138 and 132, in spaced relationship. with rcconductivity (i.e.,,above 0.2 or 0.3. calories per degree per second at 100 C.) to insure even and rapid heat transfer to the inside surfaces of yarn contact" members 130Iandf 132. r l I v v The annular heat distributing member 128 is heated by an electrical resistance heater 138 which is securedto one side face ofthe member :128 by any suitable means andextends substantially the entire distance around the side face of member 128. The electrical resistance heater 138 is supplied with an electriccurrentby means of conductor 140 which extends from one end of heater 138, axially of shaft 112, to a slip ring 142 insulated-from shaft 1 12. The other end of heater138-is grounded to heat distributing member 128 which is supported by legs126, hub;124and I shaft 112, all providing in sequence an electrical return circuit to a second slip ring 1 44 which is threaded onto. asmaller ,sect ionof shaft 112.- A carbon brush 145is mounted injasuitable holder 146 and is in sliding contact with slip ring 142, and a second carbon brush 148, mounted in a holder. 149, is inelectrical contact with slip ring.144. To complete the electrical circuit, brushes145 n and 148 are connected :to a suitablesource, of electrical power preferably through. a variableftransformer, rheostat or the like, so that the energy supplied to heater 138 can readily becontrolled to maintain the yarn contact members 130 and 132at a proper temperature. To further reduce the heat loss from the heated surfaces of heater 108, a disc of insulating material 150 is disposed between the member 12 8 and :the adjacentface of housing The discs of insulating material 150* and.152 are held in position by end plates 156; and 1,57fand by'a plurality of bolts 158 which extend through thet'wo discs of insulating fmaterial and clamp the same against-opposite side faces ofannular member'128. 1 a i Afterpassing i113 partial wrap about yarn heater 108,, within grooves 134 of member'130, the yarn ends .20 and s 22 are withdrawn in a sharply angular manner about the sharpened edge 159of1a blade member 160 such that the edge 159 is positioned atthe apexof the. acute anglein the yarn path. The blade edge1 59 is 'operatively posi tioned in such close proximity to yarn contact member 130 of heater .108 that the yarn ends 20' and 22 have little opportunity to cool before their contact with the, blade edge and are atan elevated temperature as theyfpass about s, the blade edge. The blade member 160 isheld in position of member 128 and threelegs are generally sufficient. n AlsoQthe legs 126,-and the sleeve member 118"are prefer-1 Iably formed of a material such as stainless steel having a relatively low coefficient of thermal conductivity (ie bes 1owf0.l or 0.2 calories per second per-=degreel centigrade at 100 C.) so thatthe. heat loss by conduction and the by a blade holder mearis, generally indicated by the-reference numeral 162, which will subsequently be described indetaih a v v i To assist in guiding the yarn ends 20 and 22 about the edge of blade member 160 and to aid in controlling the 1 tension in the yarn ends 20 and 22 as they. pass about edge 1 59, thereis provided an unheated roll indicated by TOT spect to each other. Yarn contactmembers130 and 1 32 i are subject to considerablewear asa result of being coni reason they are preferably madeof a wear resistant mad the reference numeral 164. [The roll 164 can be. suitably formed. from stainless steel or any'otherw-ear resistant 1 material and preferably. has a smooth peripheral surface against which the yarn 611(1810 and 22V canbe passed in sliding frictional contact, Rolll64 is carried by a. shaft 166 which is journaled' through a bushing-168 and is freely rotatable by virtue of anti-frictionbearings170 and 172. Bushing 168 is mounted within a slot 174 in the side face of housing 52 and is retained in position bya nut 17?. Y which threadably engages the externally extending eiid of the bushing.

Fromroll 16 4the yarn ends 20 and 22 are passed'to I a guide means-178here illustrated as being of the helical l j type. Helical guide 178 serves to retain the yarn ends 20 and 22 in spaced relationship with respect to each other and is carried by an arm member 130 which is secured to housing 52 by a screw 182. From guide 17 8 the yarn ends 20 and 22 are again passed to yarn advancing means 76, are wrapped one or several turns about the smaller diameter portions 88 and 92 of rolls 74 and 82 and are thereafter passed to a comb type guide 184 which again serves to retain the yarn ends 20 and 22 in spaced relationship with respect to each other. From guide 134 the yarn ends 20 and 22 pass in a partial wrap about the heated annular member 132 of yarn heater 108 and thereafter about a pin guide member 186 carried by arm 186-. The yarn ends 2t? and 22 are then passed to a second yarn advancing means generally indicated by the reference numeral 188.

The yarn advancing means 188 is generally similar to yarn advancing means 76 and comprises a first roll 1% carried by a shaft 192 which is journaled through a bushing 193 and which is freely rotatable by virtue of antifriction bearings 194 and 196. Bushing 193 extends through a slot 200 in housing 52 and is secured in posi tion by a nut 202. A support plate 204- is secured between housing 52 and nut 202 so that it is adjustably pivotable about the axis of roll 1%, and carried by plate 204 is a stub shaft 206 about which a second roll 2% is journaled. Rolls 190 and 238 are in each instance provided with a peripheral groove designed to guide a cylindrical belt member 210 which insures that the two rolls are rotated at the same surface speeds. the axis of rotation of rolls 1% and 208 are at an angle to each other so that a plurality of turns of yarn Wrapped about the two rolls remain spatially separated from each other. From yarn advancing means 188, yarn ends 20 and 22 are passed to the oil roll 34 and take-up means 42 in the manner previously described.

Extending through the lower bottom portion of housing 52 is a drive shaft 212 which is driven in synchronism with the drive means for take-up means 42 and which can conveniently extend the length of a twister frame and serve a plurality of positions of apparatus. Shaft 212 carries a drive gear 214- within housing 52 which meshes with a driven gear 216 the latter being journaled about a sleeve member 218 threaded through a suitable orifice in the wall of support housing 52. Gear 216 is freely rotat-' able by virtue of bearing 22% and has secured to one of its side faces a first disc shaped clutch member 222 of a clutch generally indicated by the reference number 223. Clutch member 222 is designed to engage a second clutch member 224 carried by one face of a multiple gear 226 journaled for rotation on antifriction bearings such as ball bearings 228 positioned on a stub shaft 239 which extends through sleeve'218. The interior surface of sleeve member 218 and the surface of stub shaft are provided with matching threads so that by rotation of stub shaft 230, it is moved axially to effect engagement or disengagement of clutch 223. A pinion 232 is secured to one end of stub shaft 230 by means of a set screw 234 and meshing with pinion 232 is a gear rack 236 on one end of a control rod member 238 whichis movable lengthwise by virtue of a roller 240 secured to housing 52 by means of a screw 242 and a second guide 244 which is secured to housing 52 by suitable means such as screws 246 and 24-3.

The control rod has a handle portion 250 which extends to the front of the apparatus to permit an operator to readily effect lengthwise movement of the control rod member 238 so that pinion 232 is rotated and clutch members 222 and 224 are brought together or separated as desired.

Multiple gear 226 constitutes a portion of the driving means for heater roll 110, yarn advancing means 76 and 18S, and cold roll .164 and permits the rate of operation of these components of the apparatus, with respect to each other, to be readily varied. The multiple gear 226 comprises a central sleeve 252 carried by the bearings 223 It will also be noticed that and secured to or formed integrally with sleeve 252 is a first gear member 254 which preferably has an even teeth. Two additional gears 253 and 260 separated by a spacer disc 262 slidably engage the sleeve 252 and are secured to gear member 254 by screws 264, 265, and 266. This construction permits one to readily exchange gear members 258 and 260 for gears of different sizes and as will subsequently become apparent, this is an advantageous feature of the apparatus.

Gear member 254 drives heater roll through a gear 268 secured to shaft 112 by means of a set screw 272 and also drives the unheated roll 164 through a gear 274 secured by means of a nut 275 to a flanged bushing 276 which in turn is secured to shaft 166 by means of a set screw 278 (see FIGURE 8). This construction is advantageous for the reason that it permits one to readily exchange gear 274 for other gears of different sizes to thereby vary the rate of operation of unheated roll 164 with respect to the rate of operation of heater roll 110. To make possible proper meshing of gears 254- and 274 with variation in the size of gear 274, a jack screw 232 is threaded through support housing 52 and abuts against bushing 168. Since jack screw 282 is approximately aligned with the slot 174 through which bushing 168 is mounted, one can by loosening nut 176 and adjusting jack screw 282 precisely position shaft 166 at varying distances from the periphery of gear 254 to accommodate gears of different sizes.

The two readily exchangeable gears on multiple gear 226 serve to drive yarn advancing means 76 and 138. Gear 260 drives yarn advancing means 76 through a small gear 284 which is secured to shaft 73 by any suitable means such as set screw 286, and gear 258 drives yarn advancing means 188 through a small gear 258 secured to shaft 192 by means such as set screw 290. The distance of shaft 73 from gear 260 is precisely adjustable by virtue of the slot 77 in housing 52, nut 7 8, and a jack screw 292 threaded through housing 52 in general alignment with the longitudinal axis of slot 77, and this permits adjustment to secure proper meshing of gear 269 and gear 284 with a relatively large variation in the relative sizes of the two gears. Similarly, the distance of shaft 192 from the periphery of gear 258 is readily adjustable by virtue of slot 200, nut 202, and a jack screw 2% so that the relative size ofgear 288 with respect to gear 258 can also be readily varied.

The above construction is exceedingly advantageous since it permits the rate of operation of both yarn advancing means 76 and yarn advancing means 188 to be varied in a systematic manner with respect to the rate of rotation of heater roll 11%. For example, if gear 254 is constructed with an even 100 teeth and gear 266 hasthe same size teeth as gear 254, a change of one tooth in gear 254 represents a change of exactly 1% in the rate of operation of yarn advancing means 76 with respect to the rate of rotation of heater 11d and the relative rate of operation of these two components can be varied in 1% steps over a relatively large range. Further, by observingthe number of teeth on gear 260 (this information can readily be stamped on one side face of each gear), subtracting the number of teeth from 100 and applying a constant, an operator can in a moment readily determine the percentage difference in the rate of advance of either section of yarn advancing means 76 and the surface speed of either section of heater roll 110. The same is true with respect to the rate of operation of yarn advancing means 188 relative to that of heater roll 110 except that in this instance the number of teeth on gear 258 is the determining factor.

Secured to the outside end face of pinion 232 by means of screws 296 and 298 is a disc cam 30!), and secured to the face of the disc cam by means of a screw 3632 is a small bushing 304 and thimble 305 about which is looped one end of a flexible cable 306. Flexible cable 306 extends through an opening 308 in housing 52 and about a trol rod 238. r

1 guidepulley 310 to the disengaging means which acts to stop operation of the-twister array 42 and insures that 320 of a solenoid 322, and by electrically connecting solenoid 322 to a conventional electrical stop motion 1 means, not illustrated, and spring biasing cable 306, automatic stopping of both the edge crimping component of p the apparatus and the take-up component of the apparatus can be simultaneously eifected upon-yarn breakage. With this arrangement control rod 233 is employed only to place the apparatus inoperation. If automatic stopping is not desired, disc cam 300 is rotated with respect to pinion 232 such that when the apparatus is in operation, cable 306 extends through the axis of rotation of cam 300, solenoid 3 22 is disconnected, and dog 312 is manually move from operative position; Both stopping and starting of the apparatus is then elfected by means of coni The reference numeral 326 indicates a support. arm.

which constitutes a part of the blade holder means 162.

i This arm has atop portion 327 i which, in normal opera: tion, extends inagenerally horizontal plane, an arcuate shank portion 328; and acentrally bored boss portion 329, and is'pivotally secured tohousing 52 by means of a pin 330 extendingthroughtihe bore of boss portion 329.

. The top portion 3270f arm 326 is provided with a gibbed way and slidablymounted in this way is a flattened arm member 332 adjustably positioned with respect to support arm 326 1 by means of an adjusting screw 334 which extends through a dependingportion 336 of arm member 332 and is itlireaded into the upper extremity of support arm 326. Adjusting screw 334 is provided with a'peripheral groove'which-engageS the inside edges of a notch 338 in the dependingportion of arm member 332' to insure that the aum'membe'r'mo'ves longitudinally with adjusting screw 334 and remains any selected position.

The right-hand end or armniember 332, as viewed in FIGURE 3 of the drawings, depends slightly and tapered to form a wedge'portion 339 having an upper face.

' detent member 348 extends through a :bore in a cylin-- I vantage of the blade holdingmeans is that it is so constructed that the yarn can be passed in light sliding con- I tact with the'bottom face of the. blade and rapidly cooled following its passage about the blade edge.

Pivotally attached to the lower portion of support arm 326 by means of a pin 346 is a rod detent member 348 having an arcuate portion 350 and a straight portion 352 with a threaded; end 354; The straight portion of rod drical stud guide 356.which is .pivotally secured to the side housing 52. A "spiral compression spring 358 is mounted on the straight portion of detent rod348" and is maintained in a compressed condition by means of nut 360so that it bears against one side of guide stud 356 and thus normally urgesarm 326to pivot ina clockwise direction as viewedin FIGURE 3 of the drawings. 'To

adjustably limit themaximum extent to which support arm 326 can be pivoted inwardly toward unheated roll 164, the support arm 326 is provided with an integrally formed tab 364 bored to received a set screw 366 which bears against housing "52 when support arm 326 is in operative position. It will .be seen that by adjustment of set screw 366 andby adjusting screw 334, both the angle that the blade 160 makes with a tangent to the periphery of heater roll 110 and the degree to which-arm member 332 extends between rolls 110 and 164 can readily'be adjusted to provide an optimum angle in the yarn path as an endyof yarn passes from heater roll 110 about i the edge ofthe blade and thereafter about unheated roll 164. The curved portion of detent rod 348' permits support arm 326 to be pivoted outwardly such that a straight line extending from the center'of -pin 346*to the axis of rotation of stud 356 passes through the pivot axis ofsupport arm 326 as the supportarmds pivoted outwardly from cold roll 164 so that the bias of spring 358 there I after urges; the support arm 326 to pivot in a counter;

position by the bias of spring 358 and the unsupported end of arm member 332 is in a convenient position for changing the blade member 160. To assist in pivoting which extends generally tangentially to the peripheral surface of heater roll member 130; and a bottomiace 5 i which extends'generally tangentially to the peripheral surface of unheated roll 164. A bifurcated spring clamp 340ha'ving a pair oflegs 341 and 342 (seeFIGURE9) is secured to the upper face of arm member 332 adjacent thewedge shaped portion thereof, and the legs" 341 and 3142 ;have portions 343 and 344 which extends through opposed notches in the sides of the arm rnember 332 generally perpendicularly toth'e longitudinal axis of the 1. arm -mem-ber. 3.42 extend generally parallel to the bottom face of wedge. shaped portion 339 and are biased against thesurface thereof by the resiliency of the spring clamp. This makes The terminalportionsfof legs 341 and it possible for one to insert a blade member between the terminal portions ofthe legs341and 342 and the EYE.

torn face'ofwedge shaped portionr339. and to abut the back edge ofthe blade member againstthe portions 343' and .344 which extend generally. perpendicularly to the f longitudinal axis of arm member 332 so, that the blade member is thereby precisely positioned with respect to:

the arm member. This simple blade holding means is also advantageous" for the reasons that'the arm member 332 can readily be' 'rnacle of copper or other-.rnetal having a relatively high thermal conductivity so 1 that heat is rapidly conducted from the blade member. A further advantage for 'the blade holding means is that wedge I: shaped portion339 extends betweenthe blade member and the heater roll and serves to partially insulate the blade member from the heater roll.- Still another ad-.

clockwisedirection as viewed in FIGURE 3. Themax. imum extent to which support arm 326 can be pivoted in this manner is limited by the contact of arcuate portion 350 of detent rod 348 with the boss portion 329 of cylindrical support arm 326, so that when the support arm is pivoted to a maximum extent in a counterclockwise direction as viewd in FIGURE 3,.it is held in thisthe support arm 326 from operative position to blade changing position and vice versa, there is provided a han- -dle 368 which can suitably be formed integrally with arm 326.

capstans for the yarn advancing means such that annular member of yarnheater 108 has a surface speed approximately equal to or slightly in excess of thatof portion 84 of roll 74 and preferably from about 1% to"1-5% in excess of thesurface speed of surface 84 of roll 74,

cold roll 164 has a surface speed slightly less than the surface speed'of annular member 1130 and preferably from 5% to 25% less thanthe surface speed of annular member 130, portion 88 of roll 74 has a surface speed less than the surface speed of portion 84 ofroll 74 and 7 preferably from 5% to 15% less, r01l190 has a surface speed of from 5% to 40% and preferably from '15 to 35% less than the surface speed of portion 88 of roll 74,

and such that. annular member 132 of heater10'8 and roll 190 have approximately equal surface speeds (i.e. preferably not more than 5% to'15% difi erenceyfiln other ,words; the apparatus is preferably set up so; that not: over feed during the edgeelasticizing operation is from 5% to 15% and from:"15% to 35% during the thermal post treatment operation This is true for substantially all yarns, but the exact degree of overfeednecessary for optimum results will vary with the particular type of yarn to be processed An electrical current is then supplied to heater 108 such that annular members 130 and 132 are heated toa temperature of at least about F.

In. operation, the apparatus is" equipped with gears and" and preferably a temperature of at least about 260 F., but not to such a high temperature as to result in the yarn being heated above its sticking temperature. With the clutch 223 disengaged and take-up means 42 inoperative, one or a plurality of yarns are than threaded from supply means 12 and 14 through, in each instance, one of the tension regulators 2S and 30 to guide means 62. Each of the yarn ends is then positioned in separate grooves of guide means 62 and is thereafter passed through the comb guide 66 to roll '74 of yarn advancing means 76. The yarn ends are then wrapped counterclockwise (as viewed in FIGURE 3) one or more turns about the larger diameter portions of rolls 74 and 82 and are thereafter passed through the comb guide 102 such that the teeth of the guide maintain the yarns in spaced relations-hip to each other. Each of the yarns is then placed in one of the grooves in the cylindrical member 136 of yarn heater 103 and, with support arm 326 pivoted outwardly from housing 52 so that the blade member 160 is in inoperative position, the yarn ends are drawn in a partial wrap about unheated roll 164 and to spiral yarn guide 178. Support arm 326 is then pivoted such that blade member 160 is disposed between rolls 164 and 110 and, such that the yarn ends pass about the blade member in an acutely angular path with the edge of the blade at the apex of the angle. The yarn ends are then threaded through spiral guide 178 such that they are retained in spaced relationship to each other and are passed one or more turns about the smaller diameter portions of rolls 74 and 82. The yarn ends are than threaded through comb guide 184 such that they are maintained in spaced apart relationship and each of the yarn ends is placed in a different one of the grooves in annular member 132 of yarn heater 108 and are led in a partial Wrap around the yarn heater, about guide pin 136 and to yarn advancing means 138. The yarn ends are then wrapped one or more turns about rolls 190' and 20%, passed into contact with oil roll 34 through a partial wrap, and are then drawn through guide means 4-3) to the twister array 42. The apparatus is then placed in operation by means of control rod 238 and runs without further attention until a yarn supply becomes depleted or a takeup package becomes filled to capacity except that if a yarn end breaks, operation of the apparatus is automatically terminated by solenoid 322 in the manner previously described.

In the above description of one specific embodiment of the apparatus and the method for using the same it has been assumed that the apparatus is to be employed for performing a combination of edge elasticizing and thermal post-treatment operations, but .as previously mentioned the apparatus can be employed to perform either of these operations individually. To perform an edge elasticizing operation Without a thermal post-treatment operation on one or a plurality of yarns, the .apparatus is threaded as previously described except that after passing about cold roll 164, the yarns are about guide pin 1% and are thereafter passed to yarn advancing means 183 without being advanced a second time by the yarn advancing means 76. Gears are then selected such that the relative rate of operation of yarn advancing means 76 and yarn advancing means 138 is such as to provide a proper degree of overfeed for edge elasticizing the particular yarn being processed.

To perform a thermal post-treatment operation on one or more ends of yarn without performing an edge-elasticizing operation, the apparatus is threaded as described for performing both operations except that the yarn is withdrawn from heater roll 110, passed about guide pin 186 with or without contact with cold roll 164 and is thereafter passed directly to yarn advancing means 188 without being advanced a second time by yarn advancing means 76. Contact With cold roll 1&4 is usually advantageous since it results in more rapid cooling of the yarn and enables one to maintain the yarn under a lower tension at the point where it departs heater roll 110.

Gears are then selected to result in yarn advancing means 76 and 188 being operated at a proper rate to give the desired degree of overfeed for a thermal post-treatment operation. Of course, in this procedure it is necessary that an elasticized yarn or yarns be furnished by the yarn supply means 12 and 14 since the yarn is not passed about the edge of the blade member and, in fact, the blade member 160 may be completely removed when the apparatus is employed for this purpose. In this respect it should also be mentioned that the degree of overfeed required for best results with torque elasticized yarns is generally much less than that required with edge elasticized and mechanically crimped yarns and whereas from 15% to 35% overfeed generally gives the best results with edge elasticized and mechanically crimped yarns, from 5% to 20% overfeed generally gives the best results in performing a thermal post-treatment operation upon torque elasticized yarns.

Apparatus employed in the process according to this invention can also be employed to thermally shrink unelasticized thermoplastic yarns, for example, in the manufacture of welt yarns for ladies hosiery, and represents a material advance over the apparatus presently employed for this purpose. Commercially available thermoplastic yarns generally have from about 5% to 25% residual shrinkage so that they will shrink by this amount when subjected to the elevated temperatures employed in boarding, scouring, and dyeing operations, and it is necessary that this residual shrinkage be eliminated before the yarns are employed in the knitting of the Welt portion of ladies hosiery or for other similar purposes since, otherwise, subsequent shrinkage of the yarn will distort the stitch and shape of the finished fabric or knit article. At the present time, the most common procedure for removing the residual shrinkage from thermoplastic yarns comprises winding the yarn upon a collapsible core and thereafter heating the yarn in a steam chamber or the like. This procedure has the disadvantage that it results in the yarn being held at an elevated temperature for a prolonged period with consequent yellowing and loss in tensile strength. It is a further disadvantage of such a procedure that the yarn throughout the yarn package is not evenly contracted so that when the yarn is thereafter formed into fabrics, the resulting fabrics do not have a uniform appearance. It has also been suggested that thermoplastic yarns be heat contracted by passing them into contact with a stationary heater, but this procedure has not met with any appreciable degree of commercial success for the reason that if the yarn is placed under sufficient tension to attain a satisfactory degree of contact with the yarn heater, the tension in the yarn is so high that good thermal shrinkage is not attained, and if one places the yarn under a sufiiciently low tension to obtain good thermal contraction, a satisfactory degree of contact with the yarn heater is not obtained. The last mentioned procedure has the further disadvantage that the yarn is unnecessarily abraded as a result of its rubbing contact with the yarn heater.

Apparatus employed in the process according to the present invention makes possible a procedure for thermally contracting thermoplastic yarns with none of the above disadvantages. With this apparatus the yarn engaging surface of the yarn heater moves with the yarn so that there is no abrasion of the yarn and a high tension to drag the yarn over the heater surface is not required. The yarn can be introduced to the moving heated surface under sufficient tension to obtain an excellent degree of ribboning of the yarn and intimate contact of all of the filaments of the yarn with the yarn heater, and can be withdrawn from the moving heated surface under such a low tension that an excellent degree of shrinkage is obtained. Because of eificient heat transfer to the yarn, it is possible to employ an exceedingly short period of heating so that there is little or no yellowing of the yarn, a minimum of loss in strength by the yarn, and the yarn can be processed at a very rapid rate. Further, positively feeding-the yarn to the heater at a selected linear rate and withdrawing the yarn from: the heater at a selected constant linear rate inherentlyresultsinthe yarn-being uniformlycontracted so that fabrics formed therefrom have i a uniform appearance.

To employ the apparatus as above described: for ther! age in the yarn as possible, the rate of overfeed by advancing means 76 with respect to means 188 should gen erally be the maximum possible without the yarngoing slack. or, in other words, from to 40% depending upon the residual shrinkage in the particular yarn being processed. In this process, the surface speed of the yarn heater can be varied fromja rate approximately equal to that at which the yarn is advanced by means76 to the rate at which the yarn is advanced by means 188, but to obtain better cont-act between the yarn and the heater surface, it is generally preferable for the surface speed of the heater to be approximately equal to or'slightly in excess (i.e. from 1% to 5% greater) than the rate a which the yarn is advanced by means 188.

In view of the abovediscussion it will also be seen that apparatus employed in the process according to this invention can suitablybe employed for performing a com: bined 'hot stretching and thermal contraction operation upon a thermoplastic yarn. Sucha combined operation is presently performed upon thermoplastic yarns in the manufacture of tire cord and the like, and particularly in the case of polyethylene terephthlate yarns and nylon 66 Patent No. 3,028,653. .15

yarns results in a product having a higher tensile strength,

. a higher modulus of elasticity, and a product which is a more stable than can "be produced by means of a thermal contraction operation alone. Apparatus is presently available for satisfactorily performing a combined hotstretching and thermal contraction operation in the manufacture of tire cord from thermoplastic y'arns, but the ap paratus of this invention nevertheless represents a material 7 advance for the-reasons that it is simpler and more versatile than the apparatus presently available. In addition, it results in a more satisfactory product for the reason that the part-icularyarnheing processedi amount that the? most instances, it is advantageous to select gears for the apparatus such that the yarn is contracted the maximum amount possible or, in other, words, from5% to 25% depending upon the particular yarn being processed.

Apparatus employed in the process according tothis invention is also suitable for performing a combination 'hot stretch and edge elasticizing operation according to the method of US. application S. N. 630,325, now US;

In this type of combined operation the apparatus is threaded and operated as above described for performing an edge elasticizing operation alone except that in this instance heater roll 108 is geared relative to'yarn 'advancingmeans 76 and 188 such that the yarn is hot stretched as it passes from advancing means 76 to the heater roll. v

There are also various other procedures for threading up apparatus as above described to perform various com-, hinations of operations such ascold drawing, hot stretching, thermal contracting, heat-setting, edge elasticizing, thermal post-treating, oiling, and plying. For example, one or several yarns can be passed from guide 62 to advancing means 188 and cold drawn as they are passed about pin 186 to the first section of advancing means 76 and thereafter thermally contracted as they are passed about heater'roll 108 to the second section of advancing means 76; or one or several yarns canhe passed from guide 66 to thefirst section of yarn advancing means 76, hot stretched as they are then passed through guide means 102 to the first section'of heaterroll 188, passed again through guide 102 and back to the first section of heater roll 108 so that they are incontact with this section of the heater roll through more than 360, thermally contracted as they are passed to thexsecond section. of advancing means 76 and heat-set as they are passed about the second section of heater roll 108 to yarn advancing means 188. If it is not desired that the yarn or yarns be ing means 188. through appropriate guide means to thethe thermal contraction step of the combined operation a can be more efficiently performed. i

To perform a combined hot stretching and thermal contraction operation with apparatus as above described, the

.. apparatus is threaded as for performing a thermal posttreatment operation on an elasticized yarn, and gears are then selected which result in the yarn heater havingasurj face speed in excess of that atvwhich the yarn is advanced oy means 76 and by means 188:; The fact that the yarn heaters surface speed is in excess of the rate at which the .yarn is advanced by means 76 results in the yarn being hot stretched as it enters into contact with theiheater for the reason that the yarn has a lower tensile strength at an elevated temperature. In other words, as the yarn :approaches the yarn heater, it is heated by. radiation and for a short distance afterthe yarn contacts the heater the degree of contact is so slight that the yarn can readily slide over the surface of, the heater, and since'the yarn has a lower tensile strength when heated, stretehingof the yarn is confined to azone extending from a point in the yarn l pathimmediately prior to that at which the yarn contacts the heater to a point in the yarn path where the degree of contact between the yarn and the heater surface is sulficient to prevent the yarn from sliding upon the heater surface. The yarn can be hot stretched at this point in the yarn path any desired amount'short of that at which oiled, they can be passed directly from the yarn advanctake-ujpmeans '42 so that they do not contact the oil roll and, When a plurality of yarn ends are being processed they can :be collected individually without being plied together by the provision of separate take-up means for each end of yarn.

In view of the above description, various other modifications in thefapparatus employed in the process of this invention and procedures for employing the same will be.

readily apparent to those skilled in the art. Having thus described our invention and one specific embodiment thereof, what we desire to claim and secure by Letters Patent is: a

1. A method for producing a high bulk yarn having an elastic nature which comprises passing a multifilament thermoplastic yarn heated to an elevated temperature about a sharp edge in an acutely angular path with said edge positioned at the apex of the angle in said path, cooling said yarn and immediately thereafter positively advancing said yarn in an unheated state onto a moving heated surface, While the yarn is free from lateral restraint,

the rate of movement of said heated surface being less 16 ing temperature of said yarn, while the yarn is free from References Cited in the file of this patent lateral restraint, the rate of movement of said heated sur- UNITED STATES PATENTS face being from 5% to 40% less than the rate at which J l 27, 1943 sa1d yarn 1s first advanced, and thereafter positively withg g gi zg aL v 52 7 1943 drawing d yarn fr m aid hfiatfid surface at a linear Nov. 30,

rate which is less than said first linear rate and is not more than about 15% dilfcrent from the rate of movement of FOREIGN PATENTS said heated surface. 563,452 Belgium Jan. 15, 1958 

1. A METHOD FOR PRODUCING A HIGH BULK YARN HAVING AN ELASTIC NATURE WHICH COMPRISES PASSING A MULTIFILAMENT THERMOPLASTIC YARN HEATED TO AN ELEVATED TEMPERATURE ABOUT A SHAPE EDGE IN AN ACUTELY ANGULAR PATH WITH SAID EDGE POSITIONED AT THE APEX OF THE ANGLE IN SAID PATH, COOLING SAID YARN AND IMMEDIATELY THEREAFTER POSITIVELY ADVANCING SAID YARN IN AN UNHEATED STATE ONTO A MOVING HEATED SURFACE, WHILE THE YARN IS FREE FROM LATERAL RESTRAINT, THE RATE OF MOVEMENT OF SAID HEATED SURFACE BEING LESS THAN THE RATE AT WHICH SAID YARN IS ADVANCED THERETO, AND POSITIVELY WITHDRAWING SAID YARN FROM SAID HEATED SURFACE AT A LINEAR RATE APPROXIMATELY EQUAL TO THE RATE OF MOVEMENT OF SAID SURFACE. 